My research is in the area of high-energy nuclear physics, where one uses extremely energetic particles to study fundamental properties of strongly interacting systems. Most of my work is carried out using the STAR detector at RHIC, the relativistic collider at Brookhaven National Lab, which provides beams of polarized (spin-aligned) protons at energies up to 250 GeV. At the resulting collision energies of 500 GeV, the polarized quarks in one proton serve as efficient and calibrated probes of the partons in the other, allowing one to map out the behavior of the quarks and gluons inside a tightly bound hadron. Some of the specific topics we are working on include:

using the quark + gluon -> quark + photon "QCD Compton" process to determine the extent to which gluons (force carriers of the strong interaction) contribute to the total spin of the proton

using W and Z boson production to study the virtual anti-quarks in the nucleon sea, in order to better understand their origin

using transversely polarized protons to measure spin asymmetries at far-forward angles that are sensitive to possible orbital motion of partons (quarks and gluons) inside the proton

The IU group has also constructed and maintains one of the major detector subsystems used in STAR, the Endcap Electromagnetic Calorimeter (EEMC), a 30-ton device that makes possible several of the measurements mentioned above. We have also made major contributions to the fast front-end electronics used by other parts of the STAR detector.